PWHT on P11

[Eduardo1982]

Dear guys:
I have a question, I have a contractor that have qualified a PQR for P Number 4. (famous "P11 material")
In this one the PWHT is specified, and the thickness range to be applied is within 5-42 mm.
ASME B31.1 establishes that pipe material thickness less than 13 mm. is not required to apply PWHT. but sounds contradictory according with this PQR qualified. In my opinion, PWHT must be applied. Whats your opinion and recommendation?
Thanks in advance.

 

[metengr]

There is nothing contradictory, the requirement for PWHT is established by the construction code, like B31.1, and not Section IX. That is why welding procedures are qualified with and without PWHT.